1. Field of the Invention
The subject application relates to an antenna. More particularly, the subject application relates to a planar bi-directional radiation antenna.
2. Description of Related Art
Antenna is an indispensable device for many wireless communication systems, which is a main element related to a whole performance of the system. Generally, the antennas can be grouped into isotropic antennas, omni-directional antennas and directive antennas according to directivities thereof. Wherein, the directive antenna can transceive electromagnetic energy of a specific direction, so that it can be widely used in fixed direction-based wireless communication systems.
The antenna having a bi-directional radiation function is mainly used to implement communication of three fixed locations, so that directivity thereof is highly required. A general bi-directional radiation antenna or device generally applies two antenna units (i.e. radiators), for example, two patch antennas or slot antennas to implement the bi-directional radiation. However, according to such conventional method, not only complexity, cost and size of the antenna are increased, but also implementation of a symmetric bi-directional radiation effect cannot be achieved (for example, due to a disposing position of a feeding structure), or a high directivity cannot be achieved (for example, due to inadequate system grounding area of the patch antenna). Therefore, the subject application provides a single planar antenna design to achieve effects such as simple fabrication, low cost, small size, symmetric bi-directional radiation and high directivity.
Moreover, by using an antenna array formed by the bi-directional radiation antennas of the subject application, in a full-space scanning, a required radiation pattern can be synthesized according to electronic signal modulation, so as to avoid using mechanical devices required by a conventional rotating antenna array, and achieve a real-time scanning without time lag.